Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Did you purchase your license from Microsoft?
Can you go to your account online via https://account.live.com
Then go to Subscriptions, do you see any Microsoft 365 plan listed? If so, what's the name of the plan?
If nothing is there, go to Order history, change the order date back a bit if needed, and see if you have any Office product listed ?
Let me know what you find out so we can continue to next steps.